Probe, treatment instrument and treatment device

ABSTRACT

A probe configured to be connected to a transducer unit configured to generate ultrasonic vibration, includes an elongated vibration transmission portion configured to transmit the ultrasonic vibration; and an engagement member provided on and/or near an outer circumference at a position which becomes a node of the ultrasonic vibration when the ultrasonic vibration is transmitted to the vibration transmission portion, the engagement member being formed by a material of an identical to or smaller damping rate than a damping rate of the ultrasonic vibration in the vibration transmission portion, and the engagement member being engaged with an exterior member disposed on an outer side of the vibration transmission portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation Application of PCT Application No.PCT/JP2016/070584, filed Jul. 12, 2016, the entire contents of which areincorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a probe which can transmit ultrasonicvibration and is used to treat biological tissues, a treatmentinstrument which includes the probe and a treatment device whichincludes a treatment instrument.

2. Description of the Related Art

For example, Jpn. Pat. Appln. KOKAT Publication No. 2010-167084discloses a probe to which ultrasonic vibration transmits. The probe isused to treat a biological body by using ultrasonic vibration. Hence,the probe has appropriate fracture resistance (strength), has a goodacoustic property (vibration transmission property), and is integrallyformed by a titanium material such as a titanium alloy material as oneexample of a material having bicompatibility.

The length of the probe is adjusted in relation to an oscillationfrequency of an ultrasonic transducer. When vibration is transmitted tothe probe, a plurality of antinode positions of vibration and aplurality of node positions of vibration are formed. At and near aposition of an outer circumference at a position which becomes a node ofvibration, an engagement portion which engages with an exterior memberis formed. Consequently, the exterior member can be used to hold theprobe.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the present invention, a probe configured tobe connected to a transducer unit configured to generate ultrasonicvibration, includes: an elongated vibration transmission portion that isconfigured to transmit the ultrasonic vibration; and an engagementmember that is provided on and/or near an outer circumference at aposition which is a node of the ultrasonic vibration when the ultrasonicvibration is transmitted to the vibration transmission portion, theengagement member being formed by a material of an identical to orsmaller damping rate than a damping rate of the ultrasonic vibration inthe vibration transmission portion, and the engagement member beingengaged with an exterior member disposed on an outer side of thevibration transmission portion.

Advantages of the invention will be set forth in the description whichfollows, and in part will be obvious from the description, or may belearned by practice of the invention. The advantages of the inventionmay be realized and obtained by means of the instrumentalities andcombinations particularly pointed out hereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a schematic view illustrating a treatment system according toa first embodiment.

FIG. 2 is a schematic vertical cross-sectional view illustrating a statewhere a treatment instrument and a transducer unit are connected in thetreatment system according to the first embodiment.

FIG. 3A is a schematic view illustrating a probe of a shaft of thetreatment instrument and a holder of a cylindrical portion in thetreatment system according to the first embodiment.

FIG. 3B is a schematic horizontal cross-sectional view along a 3B-3Bline in FIG. 3A.

FIG. 4 is a schematic view illustrating a vibration transmission portionof the probe of the shaft of the treatment instrument of the treatmentsystem according to the first embodiment.

FIG. 5A is a schematic view illustrating a state where an engagementmember is fixed to an appropriate position of an outer circumference ofthe vibration transmission portion of the probe of the shaft of thetreatment instrument, and then the holder is disposed on an outer sideof the engagement member in the treatment system according to the firstembodiment.

FIG. 5B is a cross-sectional view of the vibration transmission portionand the engagement member along a 5B-5B line including a longitudinalaxis in FIG. 5A.

FIG. 5C illustrates a modified example of a cross-sectional view of thevibration transmission portion and the engagement member along the 5B-5Bline including the longitudinal axis in FIG. 5A.

FIG. 6 is a schematic view illustrating a state where the vibrationtransmission portion of the probe of the shaft of the treatmentinstrument, and the engagement member are separated in the treatmentsystem according to the first embodiment.

FIG. 7A is a schematic view illustrating a vicinity of proximal endportion of a vibration transmission member of the probe according to amodified example of the first embodiment.

FIG. 7B is a schematic cross-sectional view illustrating a state wherethe engagement member is fitted near the proximal end portion of thevibration transmission member illustrated in FIG. 7A.

FIG. 8A is a schematic perspective view illustrating a vicinity of theproximal end portion of the vibration transmission member of the probeaccording to the modified example of the first embodiment.

FIG. 8B is a schematic cross-sectional view illustrating a state wherethe engagement member is fitted near the proximal end portion of thevibration transmission member illustrated in FIG. 8A.

FIG. 9A is a schematic perspective view illustrating the vicinity of theproximal end portion of the vibration transmission member of the probeaccording to the modified example of the first embodiment.

FIG. 9B is a schematic cross-sectional view illustrating a state wherethe engagement member is fitted near the proximal end portion of thevibration transmission member illustrated in FIG. 9A.

FIG. 10A is a schematic view illustrating a state where an outercircumferential surface of the engagement member is irradiated withlaser light in a state where an engagement member of a cylindrical shapeis disposed near the proximal end portion of the vibration transmissionmember of the probe according to the modified example of the firstembodiment.

FIG. 10B is a schematic view illustrating a state where the irradiationof the laser light illustrated in FIG. 10A changes a crystal state of anirradiated position, bulges the irradiated position, produces a stressin the engagement member, and holds the outer circumferential surface ofthe vibration transmission portion at a distal end portion and theproximal end portion along the longitudinal axis of an innercircumferential surface of the engagement member.

FIG. 10C illustrates a modified example of the example illustrated inFIGS. 10A and 10B, and is a schematic view illustrating a state wherethe vibration transmission portion is held by an engagement portion at aposition apart along the longitudinal axis from the outercircumferential surface at a position which becomes a node of vibration.

FIG. 11A is a schematic view illustrating a vicinity of the proximal endportion of the vibration transmission member of the probe according tothe modified example of the first embodiment.

FIG. 11B is a schematic cross-sectional view illustrating a state wherethe engagement member is fitted near the proximal end portion of thevibration transmission member illustrated in FIG. 11A.

FIG. 12A is a schematic perspective view illustrating the vicinity ofthe proximal end portion of the vibration transmission member of theprobe according to the modified example of the first embodiment.

FIG. 12B is a schematic cross-sectional view illustrating a state wherethe engagement member is fitted near the proximal end portion of thevibration transmission member illustrated in FIG. 12A.

FIG. 13A is a schematic perspective view illustrating the vicinity ofthe proximal end portion of the vibration transmission member of theprobe according to the modified example of the first embodiment.

FIG. 13B is a schematic cross-sectional view illustrating a state wherethe engagement member and a pin are fitted near the proximal end portionof the vibration transmission member illustrated in FIG. 13A.

FIG. 14A is a schematic perspective view illustrating the vicinity ofthe proximal end portion of the vibration transmission member of theprobe according to the modified example of the first embodiment.

FIG. 14B is a schematic cross-sectional view illustrating a state wherethe engagement member is fitted near the proximal end portion of thevibration transmission member illustrated in FIG. 14A.

FIG. 15A is a schematic perspective view illustrating a state where theengagement member is fixed near the proximal end portion of thevibration transmission member of the probe according to the modifiedexample of the first embodiment.

FIG. 15B is a schematic cross-sectional view illustrating a state wherethe engagement member is fitted near the proximal end portion of thevibration transmission member illustrated in FIG. 15A.

FIG. 16 is a schematic cross-sectional view illustrating a state wherethe engagement member is fixed near the proximal end portion of thevibration transmission member of the probe according to the modifiedexample of the first embodiment.

FIG. 17 is a schematic view illustrating a treatment system according toa second embodiment.

FIG. 18A is a schematic view illustrating a state where an engagementmember is fixed to an appropriate position of an outer circumference ofa vibration transmission portion of a probe of a shaft of a treatmentinstrument in the treatment system according to the second embodiment.

FIG. 18B is a schematic cross-sectional view along an 18B-18B line inFIG. 18A.

DETAILED DESCRIPTION OF THE INVENTION

Embodiments for carrying out the present invention will be describedbelow with reference to the drawings.

First Embodiment

First, a first embodiment will be described with reference to FIGS. 1 to6.

As illustrated in FIG. 1, a treatment system 10 includes a treatmentdevice 12 and a controller 14 which includes a power supply. An examplewhere the treatment device 12 according to the present embodiment cantreat biological tissues by ultrasonic vibration and high frequencyenergy will be described. Naturally, the treatment device 12 may be ableto treat biological tissues only by ultrasonic vibration.

The treatment device 12 includes a treatment instrument 22, and atransducer unit 24 which is used in a state fixed to the treatmentinstrument 22. The transducer unit 24 includes a built-in transducer 64described below, and is connected to the controller 14. Hence, when theelectric power is supplied from the controller 14 to the transducer 64,it is possible for the transducer 64 of the transducer unit 24 togenerate ultrasonic vibration of an appropriate frequency. Furthermore,the treatment instrument 22 and the transducer unit 24 can supply highfrequency energy to a biological tissue between an elongated vibrationtransmission portion 82 described below, and a jaw 46 including a highfrequency electrode described below by a known mechanism.

The treatment instrument 22 includes a first button 26 a and a secondbutton 26 b. The first button 26 a and the second button 26 b areelectrically connected to the controller 14 via the transducer unit 24.When, for example, the first button 26 a is pressed, high frequencyenergy is outputted between high frequency electrodes described below ina state where the biological tissue is disposed therebetween. Hence, thetreatment instrument 22, for example, stops bleeding from a blood vesselwhen the first button 26 a is pressed. When the second button 26 b ispressed, high frequency energy is outputted between the high frequencyelectrodes in a state where the biological tissue is disposedtherebetween, and electric power which generates vibration is output tothe transducer unit 24. Consequently, when the second button 26 b ispressed, the treatment instrument 22 can perform incision mainly by afunction of ultrasonic vibration while stopping the bleeding from theblood vessel mainly by high frequency energy.

The treatment instrument 22 includes a housing 32 including a shaft 34.The housing 32 is formed as a gripping portion gripped by a user such asa doctor. The housing 32 is formed by a resin material having anelectrical insulation property.

The shaft 34 includes a probe 42, and a cylindrical portion (sheath) 44which covers an outer circumference of the vibration transmissionportion 82 of the probe 42 described below.

As illustrated in FIG. 2, the cylindrical portion 44 of the shaft 34 issupported in the housing 32. The cylindrical portion 44 is itself formedby a metal material such as a stainless steel material. An outercircumferential surface of the cylindrical portion 44 is likely to comeinto contact with a patient. Hence, the outer circumferential surface ofthe cylindrical portion 44 is coated by a resin material, and has anelectrical insulation property.

The jaw 46 is supported at a distal end portion of the cylindricalportion 44 turnably around a pivotal axis perpendicular to an axialdirection of a longitudinal axis L. A position of the jaw 46 is operatedby a movable cylindrical portion 74 which is movable along thelongitudinal axis L as described below. The movable cylindrical portion74 is allowed by a slider 76 inside the housing 32 to move inconjunction with a movable handle 56 described below.

A portion of the jaw 46 which faces the vibration transmission portion82 used as the high frequency electrode is provided with a highfrequency electrode of a different pole from that of the vibrationtransmission portion 82.

In addition, an outer circumference of a portion of the movablecylindrical portion 74 which protrudes from a rotation knob 58 to adistal end side is covered by a cylindrical member 79 (see FIG. 1) madeof a stainless steel material whose outer circumferential surface isapplied an insulation coating. Although not illustrated, an innercylindrical body is disposed between the vibration transmission portion82 and the movable cylindrical portion 74. An outer circumferentialsurface at a position which becomes a node P of vibration on the outercircumferential surface of the vibration transmission portion 82 isprovided with a rubber lining 83 (see FIG. 3A) used as a spacer disposedbetween the outer circumferential surface and an inner circumferentialsurface of the inner cylindrical body. In addition, a recess portion 82c is formed on the outer circumferential surface at a position to becomethe node P of vibration on the outer circumferential surface of thevibration transmission portion 82, and the recess portion 82 c preventsmovement of the rubber lining 83 along the longitudinal axis L.

Although description of the housing 32 is omitted as appropriate sincethe housing 32 is known, the housing 32 includes a main body (grippingbody) 52 and a fixed handle 54 which is provided to the main body 52.The movable handle 56 is disposed in the housing 32. The movable handle56 is biased apart from the fixed handle 54. In this case, the jaw 46 atthe distal end of the cylindrical portion 44 is apart from an endeffector 94 of the vibration transmission portion 82. The user (doctor)can place the movable handle 56 close to the fixed handle 54. Inconjunction with this operation, the jaw 46 at the distal end of thecylindrical portion 44 turns around the pivotal axis perpendicular tothe axial direction of the longitudinal axis L, and comes close to theend effector 94 of the vibration transmission portion 82.

Similarly, although description of the main body 52 is omitted asappropriate since the main body 52 is well known, the main body 52 of acylindrical shape of the housing 32 is provided with a rotationoperation knob 58 coaxially with the longitudinal axis L. The rotationknob 58 is rotatable around the longitudinal axis L with respect to themain body 52 of the housing 32. In this case, as described below, as therotation knob 58 rotates, the cylindrical portion 44, the jaw 46 and theprobe 42 rotate together. As the rotation knob 58 rotates, not only thecylindrical portion 44, the jaw 46 and the probe 42 but also thetransducer unit 24 rotate together.

The transducer unit 24 includes a case 62, a transducer 64 which isdisposed inside the case 62 and generates ultrasonic vibration whenreceiving a supply of electric power, and a transducer side transmissionportion 66 which is fixed to the transducer 64, and transmits vibration(vertical vibration) generated by the transducer 64. A proximal end ofthe transducer side transmission portion 66 is fixed to the transducer64. A connection portion 66 a which is detachably fixed to the vibrationtransmission portion 82 is formed at a distal end of the transducer sidetransmission portion 66. In this case, the connection portion 66 a isformed as a female screw. The connection portion 66 a corresponds to anantinode of vibration when vibration is transmitted from the transducer64.

The cylindrical portion (exterior member) 44 of the shaft 34 includes aholder (exterior member) 72 which is formed from a material having anelectrical insulation property, and the movable cylindrical portion 74which is provided on an outer side of the holder 72. The movablecylindrical portion 74 is formed by a conductive material, and ismovable along the longitudinal axis L with respect to a transducer case62 and the holder 72. The slider 76 formed from an insulation materialis provided on an outer circumference of the movable cylindrical portion74. The slider 76 is movable along the longitudinal axis L with respectto the movable cylindrical portion 74. The slider 76 and the movablecylindrical portion 74 are connected via elastic members 76 a such ascoil springs. Furthermore, the movable handle 56 is attached to theslider 76. By opening and closing the movable handle 56 with respect tothe fixed handle 54, a driving force transmits to the slider 76, and theslider 76 moves along the longitudinal axis L. Furthermore, the drivingforce is transmitted from the slider 76 to the movable cylindricalportion 74 via the elastic members 76 a, and the movable cylindricalportion 74 moves along the longitudinal axis L with respect to thetransducer case 62 and the holder 72.

A conductive portion 62 a is formed in the transducer case 62. Theconductive portion 62 a is electrically connected to the controller 14.Furthermore, in a state where the cylindrical portion 44 is connected tothe transducer case 62, the movable cylindrical portion 74 of thecylindrical portion 44 movably comes into contact with the conductiveportion 62 a of the transducer case 62. Hence, in a state where thecylindrical portion 44 is connected to the transducer case 62, thetransducer case 62 and the movable cylindrical portion 74 areelectrically connected. Consequently, a high frequency current issupplied from the controller 14 to the movable cylindrical portion 74 ofthe cylindrical portion 44 via the conductive portion 62 a of thetransducer case 62. In addition, the conductive portion 62 a of thetransducer case 62 and the movable cylindrical portion 74 of thecylindrical portion 44 are electrically insulated from the vibrationtransmission portion 82.

As illustrated in FIG. 3A, the probe 42 includes the vibrationtransmission portion (main body portion) 82 which is configured totransmit ultrasonic vibration generated by the transducer unit 24, andan engagement member 84 which is attached to an outside of the vibrationtransmission portion 82. The vibration transmission portion 82 is formedby appropriately machining a columnar rod (round bar) made of titaniumor a titanium alloy material by taking into account a vibrationtransmission property, strength, a heat generation propertybiocompatibility or the like. An example where an α-β titanium alloymaterial such as a Ti-6Al-4V alloy is used for the vibrationtransmission portion 82 will be described. The columnar rod defines amaximum outer diameter D of the vibration transmission portion 82.

A distal end 82 a and a proximal end 82 b of the vibration transmissionportion 82 define the longitudinal axis L. The longitudinal axis L ofthe vibration transmission portion 82 may be formed substantiallystraight from the distal end 82 a to the proximal end 82 b, may beformed substantially straight on a proximal end side of a proximal endof the end effector 94 described below or may be bent at the endeffector 94 including the distal end 82 a.

A distance between the distal end 82 a and the proximal end 82 b of thevibration transmission portion 82, i.e., the length of the vibrationtransmission portion 82 is formed longer than the maximum outer diameter(the maximum outer diameter of the columnar rod) D of the vibrationtransmission portion 82. A connection portion 92 to which the transducerunit 24 is fixed is formed at a proximal end portion including theproximal end 82 b of the vibration transmission portion 82. Theconnection portion 92 is formed as a male screw, for example.

The end effector 94 which is configured to appropriately treat thebiological tissue when ultrasonic vibration is transmitted from theproximal end 82 b to the distal end 82 a is formed at the distal endportion including the distal end 82 a of the vibration transmissionportion 82. The end effector 94 is formed in an appropriate shape. Theend effector 94 described herein has a distal end bent by takingvisibility into account. Furthermore, the end effector 94 is formed in apredetermined shape which meshes with the jaw 46.

The length of the vibration transmission portion 82 is adjustedaccording to the frequency (wavelength) at which the transducer unit 24generates vibration. Particularly, the length of the vibrationtransmission portion 82 is adjusted so that the proximal end 82 b of thevibration transmission portion 82 becomes the antinode position ofvibration which vibrates (vertically vibrates) the proximal end 82 balong the longitudinal axis L, when vibration is transmitted from theproximal end 82 b to the distal end 82 a of the vibration transmissionportion 82.

In addition, similar to known probes, a portion which appropriatelyamplifies the amplitude when the vibration is transmitted by taperingpart of the shape of the vibration transmission portion 82 in a taperedshape whose diameter becomes smaller toward the distal end side isoptimally formed from the proximal end 82 b to the proximal end of theend effector 94.

The engagement member 84 is fixed to and/or near an outer circumferenceat the position which is the node P of the vibration which does notvibrate when the vibration is transmitted from the proximal end 82 b tothe distal end 82 a of the vibration transmission portion 82. Hence, theengagement member 84 is fixed to the outer circumferential surface ofthe vibration transmission portion 82 within a range of a region Aillustrated in FIG. 5B.

In addition, the engagement member 84 illustrated in FIG. 5C includes acylindrical body 84 b in a direction along the longitudinal axis L. Anouter circumferential surface of the cylindrical body 84 b is formedcoplanarly with the outer circumferential surface of the engagementmember 84. On the other hand, an inner circumferential surface of thecylindrical body 84 b is at a radially outside of a through-hole 84 a.In this case, a range A in which the engagement member 84 is fixed tothe outer circumferential surface of the vibration transmission portion82 is a portion except the cylindrical body 84 b.

The engagement member 84 is supported by the cylindrical portion(exterior member) 44. Hence, the probe 42 is supported by thecylindrical portion 44. The engagement member 84 is formed in a shapewhich prevents unintentional movement in and rotation around the axialdirection of the longitudinal axis L with respect to the cylindricalportion 44. Hence, an outer rim of the engagement member 84 regulatesrotation with respect to the cylindrical portion 44, and therefore isformed in a shape other than a circular shape. As illustrated in FIGS.3A and 3B, an outer shape of the engagement member 84 is formed in asubstantially cuboid shape, for example. The engagement member 84 isdisposed at a portion of the vibration transmission portion 82 havingsubstantially the same outer diameter as the outer diameter D of thecolumnar rod, and therefore has the through-hole 84 a of a circularshape which is the same as or slightly smaller than the outer diameter Dof the columnar rod. That is, the through-hole 84 a of the engagementmember 84 allows the vibration transmission portion 82 to be disposed onthe inside.

The engagement member 84 is fixed firmly to the outer circumference ofthe vibration transmission portion 82 by various fixing methods or acombination thereof described below, and is supported firmly withrespect to the cylindrical portion 44, and a material which hardlyabsorbs vibration is used for the engagement member 84. It is preferablethat a metal material is used for the engagement member 84. It ispreferable that an aluminum alloy material is used as, for example, ametal material for the engagement member 84. Furthermore, it ispreferable to use duralumin having high strength among aluminum alloymaterials for the engagement member 84. In addition, it is alsopreferable to use super duralumin or extra super duralumin differentfrom duralumin for the engagement member 84. Furthermore, it is alsopreferable to use titanium or a titanium alloy for the engagement member84. The engagement member 84 is formed by a material having a dampingrate of ultrasonic vibration which is the same as that of the vibrationtransmission portion 82 or smaller than that of the vibrationtransmission portion 82. Therefore, it is not suitable to use for theengagement member 84 a rubber material or a general resin materialhaving a higher damping rate and lower rigidity than those of thevibration transmission portion 82. In addition, it is better to avoidusing for the engagement member 84 a material of a great damping ratesuch as part of iron, a stainless alloy material or a magnesium alloymaterial even in a case of metal materials. These materials readilyabsorb vibration and therefore readily generate heat as a result, andhave a problem that the materials hardly hold an extrapolation member.

In this regard, for example, a stainless steel alloy or a magnesiumalloy material also includes a material of low vibration absorption.Hence, by selecting a material of a low vibration damping rate even in acase of a seemingly same alloy material, it is optimal to form theengagement member 84. Similarly, physically speaking, another inorganicmaterial such as ceramic or glass, or a resin material such as PPS(polyphenylene sulfide) having low acoustic attenuation (low damping)and high rigidity and hardness (high rigidity) can be used for theengagement member 84 depending on vibration conditions.

In addition, the columnar rod may be machined after the engagementmember 84 is fixed, and the vibration transmission portion 82 of desiredshape may be formed. Alternatively, the columnar rod may be machinedbefore the engagement member 84 is fixed; the vibration transmissionportion 82 of the desired shape may be formed and then the engagementmember 84 may be fixed to the vibration transmission portion 82.Furthermore, at an intermediate stage of machining of the columnar rod,the engagement member 84 may be fixed to the vibration transmissionportion 82.

As illustrated in FIGS. 3A to 5A, the holder 72 includes a first dividedbody 77 and a first divided body 78. The first divided body 77 and thefirst divided body 78 are each formed in a substantially half-pipeshape. Hence, the holder 72 is formed in a cylindrical shape by fittinga rim portion 77 a of the first divided body 77 and a rim portion 78 aof the first divided body 78.

The first divided body 77 and the first divided body 78 have recessgrooves 77 b and 78 b to which the engagement member 84 is fitted. Therecess grooves 77 b and 78 b face each other, so that the first dividedbody 77 and the first divided body 78 hold the engagement member 84 incooperation. Hence, the holder 72 is disposed on the outer side of thevibration transmission portion 82.

For example, the outer circumference of the holder 72 includes a pair ofplanes 77 c and 78 c. Hence, the plane 77 c of the first divided body 77is fitted to the inner circumferential surface of the movablecylindrical portion 74, and the plane 78 c of the second divided body 78is fitted to the inner circumferential surface of the movablecylindrical portion 74, so that the holder 72 is fitted to the movablecylindrical portion 74. The movable cylindrical portion 74 is supportedat the rotation operation knob 58 by the known mechanism.

Next, a fixing method in a case where the engagement member 84 is fixedto an appropriate position on the outer circumference of the vibrationtransmission portion 82 will be briefly described.

As illustrated in FIG. 6, the vibration transmission portion 82 isformed. First, the columnar rod made of a titanium alloy material andhaving the appropriate length is prepared. The length of the columnarrod is formed substantially equivalently to or slightly longer than thelength of the vibration transmission portion 82 which is an end product.Furthermore, the same an outer diameter portion of the outer diameter ofthe vibration transmission portion 82 which is the end product as theouter diameter D of the columnar rod is preferably formed long as muchas possible. In this case, it is possible to suppress material cost ofthe vibration transmission portion 82 of the probe 42, and reduce amachining amount. The probe 42 according to the present embodiment is ina state where a part of the outer circumference of the engagement member84 is at a distance T (see FIG. 4) from the outer circumferentialsurface of the vibration transmission portion 82. Consequently, it ispossible to save the material corresponding to the distance T in theradial direction compared to a conventional vibration transmissionportion, and reduce the machining amount.

The outer circumferential surface of the columnar rod is formed as anappropriate smooth columnar surface. The vibration transmission portion82 is formed symmetrically with respect to the longitudinal axis L, anda cross section perpendicular to the longitudinal axis L is formed in acircular shape about the longitudinal axis L. Hence, the vibrationtransmission portion 82 is formed symmetrically with respect to thelongitudinal axis L. Thus, the vibration transmission portion 82 hashigh symmetry, so that, when vibration transmits from the proximal end82 b to the distal end 82 a of the vibration transmission portion 82, itis possible to prevent occurrence of horizontal vibration and tostabilize the vibration.

In addition, the radius of the columnar rod is formed equivalently to orslightly larger than the radius at a position of the end effector 94which is assumed by the vibration transmission portion 82 to be thefarthest from the longitudinal axis L assuming that the columnar rod iscut.

Hereinafter, an example where the engagement member 84 is fixed to apredetermined position of the vibration transmission portion 82 (i.e.,to and/or near the position which becomes the node P of the vibrationwhen it is assumed that the vibration is transmitted) by shrink-fittingwill be described.

It is assumed that the transducer unit 24 is temporarily connected tothe proximal end 82 b of the columnar rod. In this case, the engagementmember 84 is fixed to and/or near the outer circumference at theposition which becomes the node P of the vibration when it is assumedthat the transducer unit 24 generates vibration, and the vibration istransmitted to the vibration transmission portion 82. When a pluralityof nodes of vibration are formed, the engagement member 84 is fixed toand/or near the outer circumference at the position which becomes thenode P of vibration on the most proximal end side, for example.

It is preferable that the engagement member 84 is fixed to the positionwhich is the node P of the vibration when the vibration is transmitted.In this regard, the node P of the vibration is defined as a point. Theengagement member 84 has the appropriate thickness along thelongitudinal axis L, and therefore the engagement member 84 is fixed notonly to the outer circumference at the position which becomes the node Pof the vibration but also to the position continuing to the vicinity ofthe outer circumference.

Furthermore, it is preferable that the engagement member 84 is fixed notto the outer circumference at the position which is the node P ofvibration, but to the vicinity of the outer circumference. That is, theengagement member 84 is not only fixed to the outer circumference at theposition which becomes the node P of the vibration, but also allowed tobe shifted more or less.

When appropriate heat is applied to the engagement member 84, theengagement member 84 slightly expands. Hence, the inner diameter of thethrough-hole 84 a becomes slightly larger. In this state, the vibrationtransmission portion 82 is inserted in the through-hole 84 a of theengagement member 84, the center of the through-hole 84 a of theengagement member 84 in the direction along the longitudinal axis L isdisposed on and near the outer circumference at the position whichbecomes the node P of the vibration of the vibration transmissionportion 82. When the engagement member 84 is cooled in this state, theengagement member 84 is fixed to the position including the outercircumference at the position which becomes the node P of the vibrationof the vibration transmission portion 82.

In this case, the outer circumferential surface of the columnar rod isformed as the appropriate smooth columnar surface. The vibrationtransmission portion 82 is formed symmetrically with respect to thelongitudinal axis L and has high symmetry, so that it is possible tostabilize the vibration when the ultrasonic vibration is transmitted.Furthermore, there is no interposed object such as an adhesive which islikely to influence transmission of vibration between the vibrationtransmission portion 82 and the engagement member 84. Consequently, itis possible to suppress loss of the vibration transmitting from theproximal end 82 b to the distal end 82 a of the vibration transmissionportion 82.

Furthermore, the end effector 94 is machined in an appropriate shape andis formed in a desired shape. The engagement member 84 may be disposedon the outer circumference of the vibration transmission portion 82, andthen the end effector 94 may be formed. The end effector 94 may beformed at the vibration transmission portion 82, and then the engagementmember 84 may be disposed on the outer circumference of the vibrationtransmission portion 82. Alternatively, in the middle of a process offorming the end effector 94 at the vibration transmission portion 82,the engagement member 84 may be disposed on the outer circumference ofthe vibration transmission portion 82.

Although the probe 42 is formed in this way, the outer diameter from thedistal end of the engagement member 84 to the distal end of the endeffector 94 is formed substantially equivalently to that of theconventional probe. Consequently, the strength of the vibrationtransmission portion 82 can be maintained at the same level as that of aconventional vibration transmission portion. That is, the strength ofthe end effector 94 can be maintained at the same level as that of aconventional end effector.

The probe 42 formed in this way is disposed in the housing 32 asillustrated in FIGS. 1 and 2.

Furthermore, the connection portion (female screw) 92 at the proximalend 82 b of the vibration transmission portion 82 of the probe 42 isscrewed to the connection portion (male screw) 66 a at the distal end ofthe transducer side transmission portion 66 of the transducer unit 24.In this case, the transducer unit 24 is fixed to the housing 32. Thevibration transmission portion 82 is electrically connected to thetransducer side transmission portion 66. Hence, when the first button 26a is pressed, the end effector 94 of the vibration transmission portion82 is used as the high frequency electrode. Furthermore, when the secondbutton 26 b is pressed, the end effector 94 of the vibrationtransmission portion 82 is used as the high frequency electrode, andultrasonic vibration generated by the transducer 64 is transmitted.Hence, while the end effector 94 is used as the high frequencyelectrode, the end effector 94 vertically vibrates in the axialdirection of the longitudinal axis L.

As described above, the following can be said for the treatmentinstrument 22 according to the present embodiment.

For example, a titanium material (titanium alloy material) used for thevibration transmission portion 82 is an expensive material itself, isdifficult to machine, and therefore is known to be highly costly.Conventionally, when, for example, a columnar rod whose maximum outerdiameter is 8 mm is machined to form a probe, a maximum outer diameterof an engagement portion which engages with an exterior member ismaintained at or close to 8 mm. On the other hand, for example, aportion (e.g., a portion on the distal end side) except the engagementportion has the outer diameter of 4 mm and has only ¼ of an area ratioleft compared to a case where the maximum outer diameter is 8 mm. Inthis case, ¾ of the area ratio of the columnar rod needs to be machinedand removed. Furthermore, the engagement portion is usually formed neara proximal end portion of the probe. Therefore, it is easy to imaginethat, when the probe becomes longer, loss of the material is greater.

According to the present embodiment, the engagement member 84 can befixed to the outer circumference of the vibration transmission portion82 later to form the probe 42. Consequently, it is not necessary toperform machining such as cutting of the material corresponding to thedistance T between the columnar rod in order to form the engagementmember 84. Consequently, it is possible to omit cutting of the materialcorresponding to the distance T between the outer circumferentialsurface of the columnar rod and a part of the outer circumference of theengagement member 84. It is possible to reduce the machining amount ofthe columnar rod which is the material as much as possible, and form theprobe 42. Although, for example, the columnar rod whose maximum outerdiameter is 8 mm is conventionally machined, the columnar rod whoseouter diameter is 4 mm can be used in advance to form the probe 42.Consequently, according to the probe 42 which adopts the structureaccording to the present embodiment, it is possible to reduce loss ofthe material as much as possible, and suppress machining cost, too.Consequently, according to the present embodiment, it is possible toprovide the probe 42 which enables reduction of the machining amount asmuch as possible, and can engage with, for example, the exterior membersuch the housing 32 and/or the rotation knob 58.

In addition, although the probe 42 is formed in this way, the outerdiameter from the distal end of the engagement member 84 to the distalend of the end effector 94 is formed substantially equivalently to thatof the conventional probe. Consequently, the strength of the endeffector 94 of the vibration transmission portion 82 can be maintainedat the same level as that of the end effector.

MODIFIED EXAMPLE 1

As illustrated in FIGS. 7A and 7B, a position (an outer circumferentialsurface at the position which becomes the node P of vibration) to whichthe engagement member 84 is attached on the outer circumferentialsurface of the vibration transmission portion 82 is optionally machinedand formed in a polygonal shape. In this case, the through-hole 84 a ofthe engagement member 84 is formed in the same polygonal shape. In thisregard, the polygonal shape is a regular hexagonal shape, and thevibration transmission portion 82 includes first to six planes 182 a to182 f on the outer circumferential surface. Hence, the outercircumference of the vibration transmission portion 82 and the first tosixth planes 184 a to 184 f of the inner circumferential surface of thethrough-hole 84 a of the engagement member 84 are fitted by a fittingstructure which places planes into contact with each other. Hence, it ispossible to prevent the engagement member 84 from moving in acircumferential direction around the longitudinal axis L with respect tothe vibration transmission portion 82 in a state where the engagementmember 84 is fixed to the vibration transmission portion 82.

FIGS. 7A and 7B illustrate a structure which enhances holding strengthof the engagement member 84 with respect to the vibration transmissionportion 82 in terms of a mechanical structure in the entirecircumference of the vibration transmission portion 82. FIGS. 8A and 8Billustrate an example of a structure which enhances holding strength ofthe engagement member 84 with respect to the vibration transmissionportion 82 in terms of a mechanical structure in a part of the vibrationtransmission portion 82. As illustrated in FIGS. 8A and 8B, thevibration transmission portion 82 includes a pair of planes 182 a and182 b to which normal vectors are directed in opposite directions. Afirst fitting plane 184 a of the engagement member 84 is fitted to thefirst plane 182 a, and a second fitting plane 184 b of the engagementmember 84 is fitted to the second plane 182 b.

Similarly, FIGS. 9A and 9B illustrate an example where a curved surfaceis used instead of the planes illustrated in FIGS. 8A and 8B. Even thisshape can enhance the holding strength of the engagement member 84 withrespect to the vibration transmission portion 82 in terms of themechanical structure.

MODIFIED EXAMPLE 2

When the engagement member 84 is fixed to the vibration transmissionportion 82, the engagement member 84 can be fixed to the vibrationtransmission portion 82 by way of adhesion. By, for example, using ananaerobic adhesive cured by blocking air, the vibration transmissionportion 82 and the engagement member 84 are fixed highly strongly.Furthermore, an adhesion time of the anaerobic adhesive can be shortenedcompared to, for example, an epoxy adhesive, so that it is possible toreduce an assembly time. In addition, the anaerobic adhesive is morereadily cured as the thickness is thinner. Hence, the anaerobic adhesiveonly needs to be formed very thin between the vibration transmissionportion 82 and the engagement member 84. Consequently, the anaerobicadhesive hardly cause occurrence of vibration loss between the vibrationtransmission portion 82 and the engagement member 84.

MODIFIED EXAMPLE 3

When the vibration transmission portion 82 and the engagement member 84are both formed by the same type of a material such as a titanium alloymaterial, the vibration transmission portion 82 and the engagementmember 84 can be fixed highly strongly by welding such as laser welding.In this case, it is preferable to remove a residual stress produced bywelding between the vibration transmission portion 82 and the engagementmember 84 by annealing or the like.

Even in a case of different types of materials which are a titaniumalloy material for the vibration transmission portion 82 and an aluminumalloy material for the engagement member 84, the vibration transmissionportion 82 and the engagement member 84 are fixed highly strongly bybrazing.

When the engagement member 84 is formed by a material of a relativelylow melting point such as the aluminum alloy material, the engagementmember 84 can be formed on the vibration transmission portion 82 bycasting. In this case, the engagement member 84 is formed integrallywith the vibration transmission portion 82, so that it is possible toobtain high adhesion.

When the engagement member 84 is formed by a material which deforms at alower temperature than the vibration transmission portion 82, theengagement member 84 can be formed on the vibration transmission portion82 by, for example, an HIP method (hot isostatic pressing method). Inthis case, the engagement member 84 is formed integrally with thevibration transmission portion 82, so that it is possible to obtain highadhesion.

When the engagement member 84 is formed by a material which is softerthan that of the vibration transmission portion 82, the engagementmember 84 can be formed on the vibration transmission portion 82 by, forexample, a CIP method (cold isostatic pressing method). In this case,the engagement member 84 is formed around the vibration transmissionportion 82 at a room temperature, so that it is possible to prevent aninfluence of the temperature.

The engagement member 84 is directly formed on the outer circumferenceof the vibration transmission portion 82 using molten metal powders,laser powder metallurgy or the like by a known 3D molding technique andcan be formed in an appropriate complicated shape.

MODIFIED EXAMPLE 4

In addition, as illustrated in FIGS. 10A and 10B, a part of theengagement member 84 may be plastically deformed to exhibit a holdingforce for the vibration transmission portion 82. As illustrated in, forexample, FIG. 10A, the engagement member 84 of the cylindrical shape isdisposed on the outer circumference of the vibration transmissionportion 82. Furthermore, the outer circumferential surface of theengagement member 84 is irradiated with laser light to change a crystalstructure of the engagement member 84. More specifically, the outercircumference of the engagement member 84 is heated and expanded alongthe circumferential direction. Hence, as illustrated in FIG. 10B, astress which holds the outer circumference of the vibration transmissionportion 82 acts on positions on a distal end side and a proximal endside adjacent to a position irradiated with the laser light. Accordingto the plastic machining, the engagement member 84 can be appropriatelyfixed to the outer circumference of the vibration transmission portion82.

In addition, it is also preferable that, as illustrated in FIG. 10C,areas A1 and A2 shifted along the longitudinal axis L from a positioncorresponding to the outer circumference of the node P of vibration areheld by the engagement member 84. In this case, the engagement member 82holds the vibration transmission portion 82 at a plurality of positions,so that it is possible to enhance the holding force. Furthermore, theengagement member 84 holds the position which hedges the node P of thevibration along the longitudinal axis L of the vibration transmissionportion 82. Consequently, it is possible to prevent vibration in theradial direction of the vibration transmission portion 82 fromtransmitting to the outside. Furthermore, it is possible to allow thevibration transmission portion 82 to be displaced in the radialdirection perpendicular to the longitudinal axis L of the vibrationtransmission portion 82 when ultrasonic vibration is transmitted to thevibration transmission portion 82.

MODIFIED EXAMPLE 5

As illustrated in FIGS. 11A and 11B, a recess groove 282 a is formed ina part of the vibration transmission portion 82. In this case, it ispreferable that a protrusion 284 a is formed on the innercircumferential surface of the through-hole 84 a of the engagementmember 84. Hence, the protrusion 284 a engages with the recess groove282 a, so that the engagement member 84 can be fixed to the vibrationtransmission portion 82 more firmly.

In addition, as illustrated in FIGS. 12A and 12B, the recess groove 282a and the protrusion 284 a do not need to be formed in parallel to,i.e., straight with respect to the longitudinal axis L, and only need tobe appropriately formed in a spiral shape.

As illustrated in FIGS. 13A and 13B, when the engagement member 84 isfixed to the vibration transmission portion 82, auxiliary members suchas a key and a pin can be used. In this case, it is possible to preventheating in a case where the engagement member 84 is fixed to thevibration transmission portion 82 from causing an unintentional thermalinfluence on the engagement member 84 and the vibration transmissionportion 82.

More specifically, the vibration transmission portion 82 includes, forexample, a pair of recess holes 382 a and 382 b. The engagement member84 includes through-holes 384 a and 384 b which continue to the recessholes 382 a and 382 b. The through-holes 384 a and 384 b are formed inthe direction perpendicular to the longitudinal axis L. Furthermore, afirst pin 386 a is fixed to the through-hole 384 a and the recess hole382 a, and a second pin 386 b is fixed to the through-hole 384 b and therecess hole 382 b.

When recess grooves 482 a and 482 b are formed in the directionperpendicular to the longitudinal axis L of the vibration transmissionportion 82 as illustrated in example in FIGS. 14A and 14B, for example,the engagement member 84 of a substantially U shape may be used. Theengagement member 84 includes leg portions 484 a and 484 b. The legportions 484 a and 484 b are fitted to the recess grooves 482 a and 482b, so that the engagement member 84 is fixed to the vibrationtransmission portion 82.

MODIFIED EXAMPLE 6

In an example illustrated in FIGS. 15A and 15B, the engagement member 84is formed by sheet metal working. The engagement member 84 includes ahub 584 a and a plurality of wings 584 b which extend outward from thehub 584 a. The engagement member 84 is formed by appropriately bending aplate of a cross shape including the opening 84 a. Thus engagementmember 84 is fitted to the appropriate holder 72 and is held.

When, for example, the outer circumference at the position shifted alongthe longitudinal axis L from the position which becomes the node P ofvibration is held by the engagement member 84, it is possible to makevibration in the radial direction of the vibration transmission portion82 hardly transmit to the outside.

MODIFIED EXAMPLE 7

In an example illustrated in FIG. 16, a part of the engagement member 84is made thin. In this regard, the engagement member 84 includes an innercylinder 884 a which forms the through-hole 84 a, and an outer cylinder684 b which is formed apart from the outer circumference of the innercylinder 684 a. The holder 72 is fitted to the outer circumferentialsurface of the outer cylinder 684 b. The inner cylinder 684 a and theouter cylinder 684 b are apart, so that it is possible to make vibrationto be transmitted to the vibration transmission portion 82 hardlytransmit to the outside such as the holder 72.

As described above, there are permitted various methods for fixing,molding and disposing the engagement member 84 to and/or near theposition of the outer circumference at the position which becomes thenode P of vibration when ultrasonic vibration is transmitted to thevibration transmission portion 82, and forming the probe 42. Theengagement member 84 is formed by the material having the damping rateof ultrasonic vibration which is the same as that of the vibrationtransmission portion 82 or smaller than that of the vibrationtransmission portion 82 by taking heat generation into account.

In addition, the outer shape of the engagement member 84 of the probe 42has been described as a substantially cuboid shape, yet can beappropriate set in relation to the older 72.

Second Embodiment

Next, a second embodiment will be described with reference to FIGS. 17to 18B. The present embodiment is a modified example of the firstembodiment, and members which are the same members as or have the samefunctions as the members described in the first embodiment will beassigned the same reference numerals, and detailed description thereofwill be omitted.

The first embodiment has described an example of a treatment instrument22 which sandwiches a biological tissue between an end effector 94 of avibration transmission portion 82 and a jaw 46 to perform treatment.However, an example of a treatment instrument 122 which is moved along alongitudinal axis L to perform treatment will be described. Furthermore,a rotation knob 58 is not disposed in a housing 32.

As illustrated in FIG. 17, a treatment system 10 includes a treatmentdevice 12, a controller 14 which includes a power supply and a footswitch 16. The treatment device 12 includes the treatment instrument122, and a transducer unit 24 which is fixed to the treatment instrument122 to be used.

When the foot switch 16 is pressed in a state where a user (doctor)places an end effector 194 in contact with the biological tissue, thetreatment instrument 122 illustrated in FIG. 17 transmits ultrasonicvibration to a probe 42 of the treatment instrument 122. Furthermore bymoving the probe 42 along the longitudinal axis L in a state where theultrasonic vibration transmits to the probe 42, the user can cut thebiological tissue.

Similar to the description of the first embodiment, the probe 42 oftreatment instrument 122 includes the vibration transmission portion 82and an engagement member 84. The vibration transmission portion 82 andthe engagement member 84 are formed as separate bodies.

A distal end 82 a to a proximal end 82 b of the vibration transmissionportion 82 illustrated in FIGS. 18A and 18B are within a range of amaximum outer diameter D of a columnar rod. Consequently, by, forexample, performing cutting machining, it is possible to form the endeffector 194 of an appropriate shape. In this case, it is optimal toform the end effector 194 on a distal end side of a distalmost endposition among positions which become a node P of vibration whenvibration is transmitted to the vibration transmission portion 82.

Furthermore, as illustrated in FIGS. 18A and 18B, the engagement member84 is fixed, molded and disposed at and/or near the position of theouter circumference at the position which becomes the node P ofvibration when ultrasonic vibration is transmitted to the vibrationtransmission portion 82 to form the probe 42.

Consequently, according to the present embodiment, it is possible toprovide the probe 42 which enables reduction of the machining amount asmuch as possible, and can engage with, for example, an exterior membersuch a housing 32.

Furthermore, the vibration transmission portion 82 including the endeffector 194 according to the present embodiment can be formed by simplycutting the columnar rod. In addition, by appropriately performing heatprocessing, the vibration transmission portion 82 can have appropriatestrength, appropriate ductility and appropriate toughness.

In addition, the shape of the end effector 194 of the vibrationtransmission portion 82 of the probe 42 can be appropriately set tovarious treatment devices. In a case of, for example, a hook type whichis one of the treatment devices which do not need the jaw 46, the endeffector 194 can be set to a shape having a hook portion. In addition,the shape of the end effector 194 is naturally allowed to have variousshapes. Hence, the vibration transmission portion 82, i.e., the probe 42to which the common engagement member 84 is fixed can support aplurality of types of lineups. Each probe 42 allows the commonengagement member 84 to be appropriately attached to the housing 32 withthe holder 72 interposed therebetween.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. A treatment instrument comprising: a probeincluding: an elongated main body that is configured to transmitultrasonic vibration, and an engagement member that is provided on anouter circumference of a position of the main body and/or in thevicinity of the outer circumference of the position of the main body,the position of the main body becoming a node of the ultrasonicvibration when the ultrasonic vibration is transmitted to the main body,and the engagement member being formed by a material of an identical toor smaller damping rate than a damping rate of the ultrasonic vibrationin the main body; and an exterior member that includes a holder engagedwith the engagement member and that is disposed on an outer side of themain body, the holder being configured to regulate movement of theengagement member in an axial direction of a longitudinal axis of themain body with respect to the holder, and being configured to regulaterotation of the engagement member in a direction around the longitudinalaxis.
 2. The treatment instrument according to claim 1, wherein: themain body is formed by titanium or a titanium alloy, and the engagementmember is formed by an aluminum alloy.
 3. The treatment instrumentaccording to claim 2, wherein the aluminum alloy is one of duralumin,super duralumin and extra super duralumin.
 4. The treatment instrumentaccording to claim 1, wherein: an outer shape of the engagement memberis formed in a shape other than a circular shape, and the engagementmember is configured to regulate rotation with respect to the exteriormember.
 5. The treatment instrument according to claim 1, comprising aclearance between the engagement member and the holder.
 6. The treatmentinstrument according to claim 1, wherein the engagement member includesa hole in which the main body is disposed inside.
 7. The treatmentinstrument according to claim 6, wherein the outer circumference of themain body and an inner circumferential surface of the hole of theengagement member are fitted by a fitting structure.
 8. The treatmentinstrument according to claim 1, wherein the engagement member isdirectly formed on the outer circumference of the main body.
 9. Thetreatment instrument according to claim 1, wherein the engagement memberis formed integrally with the main body.
 10. The treatment instrumentaccording to claim 1, wherein the engagement member covers the outercircumference of the position of the main body which becomes the node ofthe ultrasonic vibration when the ultrasonic vibration is transmitted tothe main body, and allows displacement of the main body in a radialdirection perpendicular to a longitudinal axis of the main body when theultrasonic vibration is transmitted to the main body.
 11. The treatmentinstrument according to claim 1, wherein: the main body includes: an endeffector at a distal end portion of the main body, and a connectionportion connected to a transducer unit configured to generate theultrasonic vibration at a proximal end portion of the main body, and thedistal end portion and the proximal end portion of the main bodyrespectively correspond to antinode positions of vibration when theultrasonic vibration is transmitted to the main body.
 12. The treatmentinstrument according to claim 1, wherein the engagement member is formedby an inorganic material.
 13. The treatment instrument according toclaim 1, wherein the engagement member is formed by a highly rigidityand low damping resin material.
 14. The treatment instrument accordingto claim 1, wherein the exterior member includes a gripping body whichis configured to hold an outer side of the holder and which isconfigured to be gripped by a user.
 15. The treatment instrumentaccording to claim 1, wherein: the exterior member is a cylindricalshape having an electrical insulation property, the engagement member isengaged with an inside of the exterior member, the main body is formedby an elongated columnar rod, and includes a proximal end connected witha transducer unit configured to generate the ultrasonic vibration, and adistal end to which the ultrasonic vibration is configured to transmit,the columnar rod defines a maximum outer diameter of the main body, andat least a part of a distal end side and a proximal end side of the mainbody at a position at which the engagement member is provided is formedas an maximum outer diameter of the columnar rod or as an outer diameterslightly smaller than the maximum outer diameter of the columnar rod.16. A treatment device comprising: the treatment instrument according toclaim 1; and a transducer unit connected to a proximal end of the probe.17. A method of assembling the treatment instrument according to claim1, the method comprising: fixing the engagement member to the outercircumference of the position of the main body and/or in the vicinity ofthe outer circumference of the position of the main body; holding theengagement member with recess grooves of a first divided body and asecond divided body which are each formed in a substantially half-pipeshape, fitting the first divided body and the second divided body, andforming the holder on an outer side of the main body; and supporting theholder to a housing configured to be gripped by a user.
 18. An exteriormember disposed on an outer side of an elongated main body and anengagement member on a probe including the main body configured totransmit ultrasonic vibration, and the engagement member provided on anouter circumference of a position of the main body and/or in thevicinity of the position of the main body, the position of the main bodybecoming a node of the ultrasonic vibration when the ultrasonicvibration is transmitted to the main body, the engagement member beingformed by a material of an identical to or smaller damping rate than adamping rate of the ultrasonic vibration in the main body, the exteriormember includes a holder engaged with the engagement member of theprobe, and the holder is disposed on the outer side of the main body,the holder being configured to regulate movement of the engagementmember in an axial direction of a longitudinal axis of the main bodywith respect to the holder, and being configured to regulate rotation ofthe engagement member in a direction around the longitudinal axis. 19.The exterior member according to claim 18, wherein: the holder includesa first divided body and a second divided body, and the holder is formedin a cylindrical shape when a rim of the first divided body and a rim ofthe second divided body are fitted.
 20. The exterior member according toclaim 19, wherein: the first divided body has a first recess groove towhich the engagement member is fitted, the second divided body has asecond recess groove to which the engagement member is fitted, and thefirst divided body and the second divided body hold the engagementmember in cooperation.